Hanford has a plan to clean up what may be the most highly radioactive spill at the nuclear reservation near the Columbia River in Washington state. The spill of radioactive material occurred in the 1980s.

Hanford officials have settled on a plan to clean up what may be the most highly radioactive spill at the nuclear reservation.

It depends on calling back into service the 47-year-old, oversized hot cell where the spill occurred to protect workers from the radioactive cesium and strontium that leaked through the hot cell to the soil below.

Radioactivity in the contaminated soil, which is about 1,000 feet from the Columbia River, has been measured at 8,900 rad per hour. Direct exposure for a few minutes would be fatal, according to Washington Closure, the company managing the long-term cleanup of the nuclear reservation.